I don't mean the quality, but the choice of pictures to convey the meaning. They should ideally match the wiki terminology. The mop suggests "janitor" rather than "administrator". The choice of physical tools for "bureaucrat" (is it a wrench and screwdriver?) is particularly symbolically jarring for me, because bureaucrats are people who sit at desks, the opposite of people who do physical labour.
Topic on Talk:XTools
Using the mop to symbolize administrator is long-steeped in wiki-culture. I've been around for 15 years, and the association predates me. The idea is that an administration is a necessary, but not glamorous, job. If you search for the word "mop" in wikipedia space (at least on enwiki), you'll find many usages. For example, this signpost article.
They may not make a lot of sense, but they are all based on community norms. E.g. the mop comes from File:Wikipedia Administrator.svg, the wrench for 'crats from File:Wikipedia bureaucrat.svg, and so forth.
